COVID-19 vaccine design: the Janus face of immune enhancement

Previous work on severe acute respiratory syndrome coronavirus (SARS-CoV) vaccines identified cellular immunopathology and antibody-dependent enhancement as potential safety issues. We discuss the implications of these findings for COVID-19 vaccine development and our approach to optimizing for safety and efficacy. Here, Hotez and colleagues highlight the two ‘faces’ of immune enhancement that could impact COVID-19 vaccine...